The Chinese mainland Wednesday reiterated the one-China policy and firm opposition to countries that have diplomatic ties with China officially contacting Taiwan authorities in any form.

"The Taiwan issue concerns China's core interests, and we hope the relevant people of the U.S. will abide by the one-China policy and the three China-U.S. joint communiques," said Ma Xiaoguang, spokesperson for the State Council's Taiwan Affairs Office, at a press conference.

The spokesperson hoped they would deal with Taiwan-related issues properly and prudently in order not to harm the overall China-U.S. relations and cross-Strait peace and prosperity.

Ma made the remarks when asked to comment on Taiwan leader Tsai Ing-wen's contact with U.S. officials while she was passing through Houston on her way to Central America.